Besides pH, phosphate type and ionic strength (increased by salt and the phosphate itself) also impact WHC. Greater ionic strength increases WHC by increasing the solubility of the myofibrillar proteins. A greater ionic strength and pyrophosphate use also compensate for lower pH, with its weaker binding.
However, a challenge exists in that, while a higher meat pH is desired for yield, a lower pH is wanted for taste and appearance. In poultry, a lower pH increases whiteness and helps avoid “pinking,” which is mistakenly associated with undercooked meats by some customers. Lower pHs also help reduce a potential “soapy” taste in products and help enhance the curing reaction. By using a stronger phosphate, such as a pyrophosphate, moderate yields can be obtained while avoiding higher pH, said Brotsky. He also reviewed two relatively new ingredients, TCP (tricalcium phosphate) and 3SP, also known as sodium pyrophosphate, trisodium monohydrogen pyrophosphate or trisodium diphosphate.
The pyrophosphate 3SP has a pH of 6.96. It can be formed by reacting SAPP (sodium acid pyrophosphate, pH of 4.3) with TSPP (tetrasodium pyro phosphate, pH of 10.4) or directly in the furnace used to synthesize phosphates. Improved meat products result when 3SP is blended with other phosphates.
One particular slide provided from a company study showed how the performance of TSPP was compared to STP in a model ham system with 20% yield extension. At lower phosphate levels, S3 and TSPP give higher yield per pound of phosphate used than STP. At higher phosphate levels, however, phosphate type is not as important, he noted. (See the chart “Phosphate Levels and Yield.”)
SAPP dissolves well, but is less useful, because of its low pH. However, TSPP’s high pH is beneficial, but is not widely used, because it has very limited solubility, especially with hard water. However, 3SP can be put into saturated 26% brine, and it will still dissolve--while possessing a neutral pH.
Brotsky summarized some of 3SP’s benefits as having good protein extraction at lower pH, as well as very good solubility. Additionally, it is a cost-effective alternative to using TKPP and complex multi-component phosphate blends.
As for regulations, 3SP meets E.U. specifications, and the company received a USDA approval letter in 2003. The ingredient’s bag label is “sodium pyrophosphate” and is labeled in the finished meat product as “sodium phosphate.”
Brotsky noted that several new blends are now available. One blend, with STP and SAPP, has a pH of about 8.1 in a 1% solution. It also dissolves quickly and is completely soluble. The blend helps avoid color problems, such as “tiger striping,” in cured products. This happens when needles are used to inject brine and a localized pH of 9-10 results, while the adjacent meat has a pH of 5.8-6. The alternating areas of high and low pHs produce stripes. The blend also helps avoid the pinking that occurs in poultry at higher pH.
Tricalcium phosphate (TCP) was another new phosphate presented to the USDA for approval. TCP traditionally has been used to calcium-fortify orange juice, but it also lightens poultry meat color. While a lower pH increases the redness reaction in cured products, it increases whiteness in uncured, lightly colored meat poultry by facilitating pigment denaturation. TCP overcomes the “graying effect” from alkaline phosphates. It is completely insoluble at the pH of meat and is flavorless and label-friendly, said Brotsky. USDA regulations allow its use up to 1.5% in comminuted poultry products, with an additional 0.5% of functional phosphates also allowed in the product, says Brotsky. Labeling for calcium enhancement cannot be used, if just the meat is present in the finished product, but can be done if the meat is only a component in a larger product, such as a meal.
In-house company research has looked at the impact of various blends on color, yields of various blends, use levels and processing parameters.
“‘Meat’ New Trends with Innovative Phosphates,” Eugene Brotsky, senior technical service representative, Innophos Inc., email@example.com
--Summary by Claudia D. O’Donnell, Chief Editor